Simultaneous recovery of metals and degradation of organic species: copper and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T).

In mixed wastewater streams, the presence of metal ions can retard the destruction of organic contaminants and the efficiency of recovery of the metal is reduced by the presence of organic species. The reduction in the efficiency of these methods is due to the formation of complexes between the organic species and the metal ions in solution. Results are presented for copper-2,4,5-T system in which both effects occur. A photolytic cell alone can achieve the complete degradation of 2,4,5-T, in the presence of TiO(2) or H(2)O(2), at pH 3.5. The addition of Cu(II) ions, however, retard the degradation of 2,4,5-T and complete mineralisation of 2,4,5-T was not achieved and the system also leaves Cu(II) ions in solution. An electrolytic cell alone can be used to recover copper in pH range 1.5-4.5 but is not capable of achieving complete disappearance of 2,4,5-T by anodic oxidation. A combined photolytic-electrolytic system is capable of achieving simultaneous destruction of 2,4,5-T and recovery of copper from mixed wastewater streams at pH 3.5. The percentage destruction of 2,4,5-T and the recovery of copper can be increased further by using a combined photolytic and an activated carbon concentrator cell system. This system can achieve the simultaneous recovery of copper and the degradation of 2,4,5-T without the use of an additional oxidants or catalysts.